Urban legend or not-high mileage carburetors

Mileage has to do with many factors.
Driving habits.
Vehicle weight.
Rear gear ratio.
Engine tuning.
Tire pressure and size.

The "magic" turbo-plates and mythological "500 mpg." carburetor are all part of marketing in America.

OPTIMIMUM Mileage is acquired by modern technology in fuel delivery(port injection) and ignition (electronic computer controlled) combined with good driving habits, not necessarily the madness of hypermiling.

 

This is absolutely the stupidest thread I've ever had the pleasure of reading! It's hilarious that some are still trying to help out the thread starter two years later.

 

The local "Old Farts" all tell about another old fart (now deceased) that bought a new Chrysler in "64 or thereabouts that got 60 mpg. He took it in to get a warranty check and "they" swapped carbs, thereafter it got 8 mpg like any other big block Mopar.
Gotta be true, it's from Coffee Row!
I've always found that the carb is the last thing that causes poor mileage, unless there's actually gas running out on the ground from it. That's assuming it's set up for the engine it's on.
A problem with fuel injection is, it's set up more for emissions than mileage.

 

In the early 1990's I had a Citroen AX diesel that got 80mpg without even trying. Buckets of torque in a small car too.

For big engine economy could I suggest a big single SU - not a magic carb but they usually give good mileage and anyone who drives a car fitted with an SU and then changes to a performance car will usually tell you that the car ran sweeter with the SU.

 

No, thats to dedflect the Police radar.

 

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And even if they wern't - (and they're not!) - they'd still probably be made in China and *definitely* be sold at Wal-Mart!

Mart3406
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I think there were probably some weird designs that attempted to do what a fuel injection system does, the idea was correct, all modern cars run on this principle, but the technology wasn't ready yet, the closest thing to it actually working in those days, was probably mechanical fuel injection. It takes a lot of fuel pressure to atomize fuel with a modern fuel injector, I don't think some of the crazy carb ideas would have worked without it. What they were probably trying to make was throttle body injection basically.

 

actually it has everything to do with the fuel system, with a modern car, the computer has an extreme amount of control over the fuel system, and is able to fine tune it in ways people couldn't have dreamed of 30 years ago , the computers know every parameter happening on the engine and adjust fuel accordingly. I personally like carbs myself but no carb can control fuel like a modern FI system. and can't match the mileage. The problem with FI though is it really takes away the soul of the car,

 

I disagree.

If you're sitting courtside, does a basketball player REALLY lose "soul" because he has on any other shoe than Chuck Taylors?

Loose "sole". Ha-ha-.

But seriously, man - I love carbs to death. But on a daily, I do love my EFI.

~Jason

 

In my experience, a large percentage of mileage problems are the carburetor.
Not even counting bad rebuilds, "rebuilt" consisting of taking it apart, looking at it, and putting most of it back together badly, wrong jets, wrong part number, gasket leaks:
The most prevalent is that the power system is stuck "on" (metering rod frozen "up", metering rod didn't seat in the jet, ruptured power valve).
Submerged float
Hot air to air cleaner hose missing
Hot air valve inside air cleaner broken
Choke unloader broken, disabled
Choke setting too rich
Somehow, even otherwise bright people actually believe that when you buy a bright shiny new carburetor for $800, it comes with the choke already adjusted, and they don't understand why it won't start and gets 4 mpg.
Except for putting the same carb back on, anything else requires a choke adjustment from square 1. If you didn't do this, it's wrong.

After that:
Punctured, disconnected vacuum advance
Low tire pressure
Runs hot? Take out the thermostat

You're not going to believe this, and I'm sure it's less prevalent than it was years ago, but some women (sorry, never heard of a man doing this) never learned to upshift.
Yes, that's right - they have to start in 1st (or it stalls), but there's not that much difference between those other thingies at 40 mph, so they don't use them. 70,000 miles in 2nd gear.
Also true of Powerglide: "They're so easy to drive, I just love them. Just put the little arrow into L!", going 65 on the Jersey Tpke. in low gear.

Read my article: http://victorylibrary.com/mopar/mileage.htm

 

I think carbs just go back to a better time, a fuel; injected engine doesn't have that sound of air being sucked through the carburetor either, you can pretty close with ITB setups, but not exactly

 

LOL I laughed good on this one. Well written.

For those who doubt, look at those little propellers. It takes work to spin them, right? So your mileage will go down. Think about it.

 

Ask the old timers about Bob Googe. Who had a carb that would get mpg's you would not believe. Ford reps came to his house and bought the carb and rights to it.Only worked on a flathead. The mph's were crap on a ohv engine. Bob died in the late 50's. He also built a little 2 seat sports car for kids .Bob was from Evansville Ind.

 

Most of those device do work, but not for the reasons they say.
They're an obstruction, they make the flow rate drop, and work almost as well as using a smaller carburetor, or the following: "don't put your foot down as far".

 

Ouch. It still takes the same power to go the same speed. So if you have to suck harder, you don't go the same speed for the same amount of gas, so you have to press harder, therefore less mileage.

 

And THAT'S why I don't put EFI on everything, nor do I recommend it.

Through my life, that very sound negated any use I may have once had for a radio.

~Jason

 

Being really late to this thread,
I had a couple of high mileage carbs my brother bought at a garage sale. I don't remember the name of them, but they were vacuum operated. They reminded me of the Predator carbs. They had a throttle blade and one big blade above it operated by a large vacuum pod in the rear. Vacuum held it shut, it made a bunch of hissing noise and was real responsive at low speeds. Mileage wasn't any better then the stock Holley two barrel, ('85 Dodge 318). I drove it for a few tanks of fuel to give it a fair test. It sucked in cold weather, ended up scrapping them, not worth the aluminum they were made from! I believe they were like the Ford vacuum carbs.

Joe

 

If you want good mileage I have a fuel economy vehicle sitting in the back of the shop. 3 scooter size wheels, aluminum body and a one cylinder air cooled diesel. Still has some of the first gallon of fuel in it. Kind of ugly, painted orange and nasty diesel sounds & smell. I quit driving it because it made my back hurt. Got well over 100 mpg.

 

Smokey Yunick did an engineering project for GM in which he fabricated a heat exchanger and homogenizer to increase fuel economy. The test engine was a Pontiac Fiero. He reported 40 mpg but was so complicated GM scrapped the idea.

 

Hey and last test when I was drinking my fish carb actually went up about 10 miles per gallon. t beat thatcan